This invention is related to the video machinery, especially having an apparatus for limiting a watching of video machinery and methods of limiting a watching using thereof, wherein the apparatus and methods are to use video signal having a certain grades.
The methods of limiting a watching of traditional video machinery are divided into three, as described hereinafter.
Firstly, it is to put the limitation on video set itself. Such method is described in Korea patent application No.87-15449 filed by applicant of the present invention. As shown in a flowchart of FIG. 1a of that patent application. After turn on the source of electric power, it is set up that the secret code must be inputted when in order to use the apparatus otherwise the apparatus is unable to be used by the customer.
Secondly, as shown in a flowchart of FIG. 1b, the set recognizing the program selected by an user. If a program being selected through user display is not an adult program, the set is in playback state, on the other hand, in case where the selected program is an adult program, the set is comparing the inputted code with originally set up secret code. If two codes are matching, the set goes into a playback state, while the set is not in function when two codes are not identical.
Thirdly, a method described in Korea patent application No.90-5219 by same applicant of the present invention, as shown in a flowchart of FIG. 1c, when the user input the code for each program, respectively, if they are identified as identical, namely, inputted secret code and originally created secret code are same, the set playbacks the program, while the set is not in function when two codes are not identical.
But, in the prior art previously discussed, some problems have been arisen such that it is impossible to selectively watch by the user because the use of the set itself is limited.
Also, the second prior art has another problem as described hereinafter, if the user display is not provided or if it is broken, or the user display is changed by the user, it is impossible to limit a watching to other viewer.
And the third one has a disadvantage that the user himself must input every secret codes for each program, respectively.